1. Field of Invention
The present invention relates to microfabricated and microfluidic structures. In one example, the present invention relates to a microfabricated system and method for genome sequencing.
2. Description of Related Art
The genome of an organism is defined by the DNA (deoxyribonucleic acid) or, for some viruses, the RNA (ribonucleic acid) of the organism. Genome sequencing is figuring out the order of the nucleotides, or bases, of a DNA or RNA strand.
A current approach to genome-scale sequencing of DNA is shown in FIG. 1. This shotgun sequencing approach 100 uses bacterial transformation, selection and growth to manipulate individual genomic DNA fragments. The first three steps of this approach, shearing, vector ligation, and transformation (steps 102, 104, and 106), need only be performed once. As such, they do not present any particular problems. The last step, the capillary electrophoresis (CE) (step 114), has been miniaturized through microfabrication. This has reduced the cost and processing time associated with this step. The plate and grow (step 108), and the pick, grow and extract steps (step 110), however, are problematic. These steps, which precede the Sanger extension step (step 112), perform clone isolation and insert amplification. The amplification may be bacterial, PCR (polymerase chain reaction) or RCA (rolling circle amplification). These steps have remained refractory to miniaturization and integration. The current macroscopic paradigm has thus relied upon the use of robotics as the enabling technology for these key steps. However, this is a problem because no less than 30 million colonies must be picked and grown to produce a sequencing template for a genome. Furthermore, the minimum quantities of materials prepared by such robotic technologies are orders of magnitude more than that required by modern microfabricated CE analysis systems.
Therefore, it is desirable to improve the processing time, volume scale, and level of integration of genome sequencing. It is also desirable to reduce the cost and space requirements of genome sequencing.